1. Field of the Invention
The present invention relates to a compressor, and more particularly, to a hermetic reciprocating compressor employed in a refrigerator or an air conditioner to compress and discharge refrigerant.
2. Description of the Prior Art
Generally, as shown in FIG. 1, a hermetic reciprocating compressor includes a sealed casing 10 made up of upper and lower shells 11 and 12, an electronic device portion 20, which is a driving source arranged in the sealed casing 10, and a compression device portion 30 also arranged in the sealed casing 10 and driven by the driving force transmitted from the electronic device portion 20 to compress and discharge refrigerant.
The electronic device portion 20 includes a stator 21, a rotor 22, and a crankshaft 23. The crankshaft 23 is press-fit to the rotor 22 and has an eccentric portion 23a formed on one side thereof.
The compression device portion 30 includes a cylinder block 31 having a compressing chamber 31a, a piston reciprocally movable in the compressing chamber 31a of the cylinder block 31 in a linear direction, and a connecting rod 33 disposed between the piston 32 and the eccentric portion 23a of the crankshaft 23 to transform and transmit the rotary movement of the crankshaft 23 to the linear reciprocal movement of the piston 32.
In the hermetic reciprocating compressor constructed as above, when electricity is supplied, the rotary movement of the crankshaft 23 is transformed and transmitted to the linear reciprocating movement of the piston 32. The piston 32 linearly reciprocates in the compressing chamber 31a of the cylinder block 31 to compress and discharge refrigerant. The high speed flow of the refrigerant produces a lot of noise. In addition, there is a lot of vibration from various valves, rotating portions, and sliding portions. In order to reduce vibration and noise produced during the operation of the compressor, the hermetic reciprocating compressor employs the following noise/vibration reducing systems.
One of the noise/vibration reducing systems employed in the hermetic reciprocating compressor is a muffler system which has a suction muffler 41 disposed in the refrigerant suction channel, and a discharge muffler 42 disposed in the refrigerant discharge channel. The muffler system significantly reduces the noise from the high-speed refrigerant flow.
Another noise/vibration reducing system is a suspension system which controls the direct transmission of the vibration produced from the electronic and compression device portions 20 and 30 to the sealed casing 10. Such a suspension system 50 absorbs or damps the vibration produced from the electronic and compression device portions 20 and 30 by elastically and movably supporting the compression device portion 30 on the lower shell 12 of the sealed casing 10. The suspension system 50 includes a plurality of snubbers 51 arranged on the bottom of the lower shell 12, a plurality of protrusions 52 protruding from the lower portion of the cylinder block 31, and a plurality of suspension springs 53 disposed between the snubbers 51 and the protrusions 52 for elastically supporting the cylinder block 31.
The reference numeral 60 refers to a crankshaft stopper for restricting the movement of the electronic device portion 20 and the compression device portion 30, which are elastically and movably supported within the sealed casing 10 by the suspension system 50 and are often vertically and horizontally moved during the conveyance of the compressor into contact with the inner wall of the sealed casing 10.
By the above-described noise/vibration reducing system, noise produced during the operation of the compressor is first reduced and controlled by the muffler system and the suspension system 50, and finally reduced and controlled by the sealed casing 10.
In the conventional hermetic reciprocating compressor described above, however, the muffler system and the suspension system only reduce the noise and vibration to a certain degree. Since the rigidity of the sealed casing 10 is too weak, the noise and vibration control efficiency is deteriorated, and accordingly, noise from the compressor increases.
After the vibration produced from the electronic device portion 20 and the compression device portion 30 is first damped or reduced by the suspension springs 53, the remaining vibration is transmitted to the sealed casing 10 through the snubbers 51. Additional noise is produced from the resonance of the sealed casing 10.
The vibration transmitted to the sealed casing 10 through the snubbers 51 is directly transmitted to the compressor without being damped or reduced, thereby contributing to and increasing the vibration and noise from the compressor.
The present invention has been made to overcome the above-mentioned problems of the prior art. It is an object of the present invention to provide a hermetic reciprocating compressor capable of lowering the noise level of the compressor by increasing the rigidity of the sealed casing with minimal changes to the design of the compressor, and thus increasing the vibration/noise controlling efficiency of the sealed casing.
Another object of the present invention is to provide a hermetic reciprocating compressor capable of damping and absorbing the vibration by dispersing the transmission paths of the vibration produced from the electronic device portion and the compression device portion and transmitted to the sealed casing. Thus, the present invention controls the resonance of the sealed casing to reduce the vibration of the compressor.
The above objects are accomplished by a hermetic reciprocating compressor according to the present invention, including: a sealed casing having an upper shell and a lower shell; an electronic device portion located in the sealed casing; a compression device portion driven by the electronic device portion to compress and discharge a refrigerant; a suspension system for absorbing or damping the vibration produced from the electronic device portion and the compression device portion by elastically and movably supporting the compression device portion on the lower shell of the sealed casing; and a casing rigidity increasing portion for exerting elasticity between the compression device portion and the lower shell, thus controlling the transmission of the noise produced from the electronic device portion and the compression device portion through the sealed casing and dispersing the vibration is transmitted to the sealed casing.
Here, the casing rigidity increasing portion is made of an elastic member which can exert elasticity between the compression device portion and the lower shell of the sealed casing, to obtain a shell rigidity similar to that which results by increasing the thickness of the shell of the compressor. Accordingly, noise and vibration controlling efficiency is increased by the sealed casing, and noise of the compressor can be reduced.
The elastic member includes a body having an annular hole in contact with the center of the bottom of the lower shell, and at least four supporting legs extending from the body which are elastically connected to a plurality of snubbers arranged on the lower shell, respectively. Accordingly, the transmission path of the vibration, which is produced from the electronic device portion and the compression device portion and transmitted to the sealed casing, is dispersed among the supporting legs, and some vibration is absorbed by the sealed casing itself. Accordingly, vibration of the compressor can be reduced.
Meanwhile, on the end of each supporting leg is a groove or connecting hole whose one end is open to permit the supporting leg to be easily fitted in the snubber. The elastic member may be made of a steel plate or a plastic material having a high vibration absorbing efficiency.